Gyratory crushers are used for crushing ore, mineral and rock material to smaller sizes. Typically, the crusher comprises a crushing head mounted upon an elongate main shaft. A first crushing shell (typically referred to as a mantle) is mounted on the crushing head and a second crushing shell (typically referred to as a concave) is mounted on a frame such that the first and second crushing shells define together a crushing gap through which material to be crushed is passed. A driving device positioned at a lower region of the main shaft is configured to rotate an eccentric assembly about the shaft to cause the crushing head to perform a gyratory pendulum movement and crush the material introduced in the crushing gap. Example gyratory crushers are described in WO 2004/110626; WO 2010/123431 and WO 2012/005651.
Similarly, vertical shaft impact crushers (VSI-crushers) are used in many applications for crushing hard material like rocks, ore etc., with examples described in WO 2004/020103 and WO 2010/042025.
Common to the various types of crushers is the need for the controlled feeding of material into the crusher in order to optimise the crushing action and crusher efficiency. Typically, a feed hopper is mounted at the crusher inlet and acts to guide material into the crushing zone. Moreover, a specific feed distributor is mounted with the hopper and acts to receive the flow of material to be crushed and to guide this material through the hopper to provide an even flow into the open upper end of the crusher. Example feed distributors are described in U.S. Pat. No. 1,920,488; FR 2,039,161; EP 1214980; CN 201192649 and U.S. Pat. No. 8,056,847.
Typically, existing feed distributors comprise a guide body having a shelf-like configuration to receive the material flow. The guide body is mounted at an inside region of the hopper walls via a mounting having adjustable components that allow positional adjustment of the guide body according to two degrees of freedom. In particular, the guide body, according to conventional mounting systems, is capable of moving side-to-side within the hopper to change a width of the guide body and to move in an upward and downward direction to change the height of the guide body relative to the hopper and in particular the underlying crusher. However, feed material is usually supplied to the hopper via a conveyor belt system and falls into the hopper as a curtain-like flow. Due to the relatively limited positional adjustment of the guide body, it is a common problem that the distributor is misaligned relative to the curtain of material resulting in non-optimised distribution of feed into the crusher and an unbalancing of the crusher operation which in turn leads to enhanced wear or damage to the crusher components. What is required is a feed distributor that addresses these problems.